The Letter by The Box Tops is in Am at 134 beats per minute and runs 1:39 across 37 bars. It uses 9 chords — N.C., Am, F, Am7, D7, F7, E7, C, and a few more. The chord diagram changes as the song plays and the words light up as they are sung, so you can strum and sing along without reading ahead.
Want the melody line note by note? The Letter guitar melody tab.